Evaluation of Undrained Bearing Capacities of Wide-Shallow Bucket Foundation with Honeycomb Bulkheads in Clay

Qingshan Wang,Wenxuan Li,Yunfei Guan,Yongyong Cao,Xun Han

doi:10.1155/2019/9769042

Qingshan Wang, Wenxuan Li + Show 3 more

Open Access

https://doi.org/10.1155/2019/9769042

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Abstract

As a new type of offshore wind foundation, the wide-shallow bucket foundation with honeycomb bulkheads mainly bears vertical, horizontal, and moment loads. As yet, no systematic study has been conducted regarding the effects of honeycomb bulkheads on the undrained bearing capacities of the wide-shallow bucket foundation. In this study, a large number of three-dimensional (3D) finite element (FE) analyses were performed to investigate the undrained bearing capacities of the wide-shallow bucket foundations with and without honeycomb bulkheads, thereby evaluating the influence of honeycomb bulkheads on the bearing capacities under different conditions. The results show that under uniaxial loading, the uniaxial bearing capacities of the wide-shallow bucket foundation are basically unaffected by the honeycomb bulkheads in homogeneous clay. For nonhomogeneous clay, the moment bearing capacity will be considerably enhanced with the increase in soil shear strength heterogeneity. Under combined loading, the honeycomb bulkheads will enhance the combined bearing capacities only in nonhomogeneous clay. The enhancement effects will increase with the increase in soil shear strength heterogeneity but decrease with the increase in vertical load. Besides, the simplified equations for calculating the uniaxial bearing capacities of the wide-shallow bucket foundation with honeycomb bulkheads are also proposed considering the influence of embedment ratio and soil shear strength heterogeneity. At last, the parameters of an approximating expression are fitted to predict the failure envelopes of this foundation under combined loading.

Highlights

As the global energy crisis continues to worsen, a source of renewable and clean energy, offshore wind energy, provides new possibilities to ease the current demands for energy and has been attracting attentions around the world
No systematic study has been conducted regarding the effects of honeycomb bulkheads on the undrained bearing capacities of the bucket foundation in clay. e effects of the honeycomb bulkheads on the undrained bearing capacities remain unclear and must be further researched
A series of 3D finite element (FE) analyses were carried out to explicitly evaluate the undrained bearing capacities of the wide-shallow bucket foundations with and without honeycomb bulkheads under uniaxial and combined loadings, respectively. e effect of honeycomb bulkheads on the bearing capacities of the wide-shallow bucket foundation under different conditions was analysed as well. e main conclusions were drawn as follows: (1) For homogeneous clay, the uniaxial vertical, horizontal, and moment bearing capacities of the wideshallow bucket foundation are basically unaffected by the honeycomb bulkheads. e honeycomb bulkheads have almost no impact on the failure envelopes of the wide-shallow bucket foundation under combined VHM loading

Summary

Introduction

As the global energy crisis continues to worsen, a source of renewable and clean energy, offshore wind energy, provides new possibilities to ease the current demands for energy and has been attracting attentions around the world. The construction of offshore wind turbines gradually becomes the subject of extensive researches, the design and implementation of offshore wind foundations. E offshore wind foundations commonly and currently used include the monopile foundation, gravity foundation, tripod foundation, and bucket foundation. As an efficient alternative for offshore wind foundations, it can adapt to deeper waters and larger offshore wind turbines [1]. E advantages of the bucket foundation include relatively low cost, environmental protection, and fast construction and installation [2] As an efficient alternative for offshore wind foundations, it can adapt to deeper waters and larger offshore wind turbines [1]. e advantages of the bucket foundation include relatively low cost, environmental protection, and fast construction and installation [2]

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